Today, one of the most significant contamination problems is that caused by hydrocarbons, whether they are spilled onto the soil or into seas and rivers. When they are spilled onto soil, the layer of polluted soil is usually removed and subjected to ulterior treatment. Until it is treated, this soil is accumulated in large piles representing a substantial liability and cost to companies. This further involves substantial soil movement consisting of both permeated and clean soil, which causes a considerable alteration to the ecosystem and high operating costs.
In the case of contaminated water, when it is fresh water, it is no longer suitable for consumption or irrigation and, when it is sea water, it directly impacts on marine or coastal life. In the case of water present deep in the substratum, it is extracted through oil well production and can then be reinjected into the reservoir in secondary oil recovery procedures. This reinjected water must not contain oil as the latter entrains solid fines that later affect the permeability of the formation and, thus, the well's productivity.
In order to decontaminate this water, complex filter systems have been developed that, as it usually happens with all filters, end up quickly occluded or blocked by the hydrocarbon and trapped particles. To maintain the operating range of the plant, the circulation pressure of the contaminated liquid must be raised to keep the flow; however, as there is insufficient pressure, the system stops functioning. Although it is always possible to increase the pressure, the pressure values reached would exceed the resistance of the filter meshes, leading to their rupture and the stoppage and/or failure of the entire system.
Even though there are techniques using enzymes or bacteria that degrade the oil, they are not commercially profitable due to their elevated cost.
There are other techniques that have used bird feathers due to their high oil sequestering potential when in contact with it; but, as we will see in the following documents, they have all used whole feathers in their natural state and, although this has yielded good results, the oil collection capability can still be improved, as proven by the inventors of this product.
Indeed, among these techniques that have failed to achieve the desired results—as evidenced by their lack of application in the most widely-known markets—is U.S. Pat. No. 4,439,324 that discloses an oil collection method by using bags full of loose bird feathers. This patent does not provide for the grinding of these feathers.
U.S. Pat. No. 4,919,820 refers to a method similar to the previous one, consisting of filling mesh bags with duck feathers, where bags are interconnected between each other and have float devices to delimit and collect oil floating on a surface. U.S. Pat. No. 5,348,661 describes a similar but more complex method, based on preparing a mesh carrier with oil adsorptive and collection material inside arranged in cells within the carrier. The oil adsorptive material is spray coated with an adhesive so as to be kept inside the carrier bags. Then, as in other known procedures, it is spread over the water surface where the spilled oil is to be collected.
Finally, U.S. Pat. No. 4,512,890 describes a filtering device to separate an oily substance, like oil, from water, consisting of an outer case with an inlet and an outlet holding a filter formed by a layer of laminar material and feathers to catch the oily fluid. This results in the usual occlusion of the filter plate due to its position crosswise to the flow of liquid, acting as a plug. The feather is all the same used in its natural state.
Another defect of the products and systems of the prior art, specially those described hereinabove and, more specifically, those using bags with sequestering material that ends up permeated with the oil, is that these final permeated products are a potential hazard both for transportation and disposal or temporary storage due to their inflammableness.
In view of the current state of technique available for hydrocarbon separation from contaminated solid or liquid media, it would be quite convenient to have an affordable and effective hydrocarbon sequestering product that further allows implementing simple hydrocarbon sequestering methods that can be carried out efficiently, cost-effectively, quickly and in plain low-cost operating and maintenance facilities.